Chronic Disease Indicators: 2022–2024 Refresh and Modernization of the Web Tool

Easy access and display of state-level estimates of the prevalence of chronic diseases and their risk factors can guide evidence-based decision-making, policy development, and tailored efforts to improve population health outcomes; however, these estimates are often presented across multiple websites and reports. The Chronic Disease Indicators (CDI) web tool (www.cdc.gov/cdi) disseminates state-level data compiled from various data sources, including surveys, vital records, and administrative data, and applies standardized definitions to estimate and track a wide range of key indicators of chronic diseases and their risk factors. In 2022–2024, the indicators were refreshed to include 113 measures across 21 topic areas, and the web tool was modernized to enhance its key features and functionalities, including standardized indicator definitions; interactive charts, graphs, and maps that present data in a visually appealing format; an easy-to-use web-based interface for users to query and extract the data they need; and state comparison reports to identify geographic variations in disease and risk factor prevalence. National and state-level estimates are provided for the overall population and, where applicable, by sex, race and ethnicity, and age. We review the history of CDIs, describe the 2022–2024 refresh process, and explore the interactive features of the CDI web tool with the goal of demonstrating how practitioners, policymakers, and other users can easily examine and track a wide range of key indicators of chronic diseases and their risk factors to support state-level public health action.


Introduction
In 2018, more than half of US adults had 1 or more of the following 10 chronic conditions: arthritis, cancer, chronic obstructive pulmonary disease, coronary heart disease, current asthma, diabetes, hepatitis, hypertension, stroke, and weak or failing kidneys (1).These and other chronic diseases are the leading causes of illness, disability, and death and the leading drivers of health care costs in the US (2).Several health risk behaviors (eg, smoking, alcohol use, physical inactivity) and social determinants of health affect the prevalence, management, and treatment of chronic diseases (2).Increases in knowledge about risk factors and conditions and recognition of social factors affecting health outcomes have led to an expanded view of the role of public health beyond viewing chronic conditions alone.
State-level estimates of chronic diseases and their risk factors can play an important role in the development of state-level policies, practices, and programs; identification of state-level priority conditions and health risk behaviors; resource prioritization and allocation; and tracking changes over time to assess progress toward state health objectives and the effect of state efforts.In the US, several surveillance systems monitor chronic diseases and their risk factors and can provide state-level estimates (eg, the Behavi-oral Risk Factor Surveillance System [BRFSS] [3], the Youth Risk Behavior Surveillance System [YRBSS] [4]).Data stewards of systems house the data on their sites and often provide summary estimates via reports or applications.In addition, many programs of the Centers for Disease Control and Prevention (CDC) present estimates of the prevalence or incidence of chronic diseases or their risk factors (5)(6)(7).However, users interested in estimates across multiple data sources and different chronic diseases and their risk factors may have difficulty in efficiently extracting data across platforms.
The Chronic Disease Indicators (CDI) web tool (www.cdc.gov/cdi) is designed to provide public health professionals, researchers, and policymakers with valuable data for the surveillance of chronic diseases and their risk factors at the national and state level.The web tool compiles data from various data sources, including surveys, vital records, and administrative data, and applies standardized definitions to estimate and track key indicators.CDI provides estimates from different data sources in the same data set to connect data across the health spectrum, from risk factors and behaviors to treatment and health care outcomes to mortality.CDI is one of the most popular sites for chronic disease data and is in the top 4% (5 of 135) of most-accessed datasets among all of CDC's chronic diseases datasets.The roots of CDI began in 1999 when a set of surveillance indicators were released by CDC, the Council of State and Territorial Epidemiologists (CSTE), and the Association of State and Territorial Chronic Disease Program Directors (ASTCDPD) (8).During the past 20 years, the indicators have changed, as has the web tool.To better serve users and to improve the efficiency of CDI, a refresh process was initiated in 2022.This process included a re-examination of the indicators and modernization of and enhancements to the web tool.

History of Chronic Disease Indicators
The original set of 73 indicators was released in 1999 by CDC, CSTE, and ASTCDPD.In 2002, the indicators were revised and expanded to 92 (8).CDC, CSTE, and ASTCDPD collaborated on the 2002 revision.Indicators were evaluated for their relevance to chronic disease prevention and control at the state level and for the availability of data on an annual or biannual basis at the state level for most states.In addition, an attempt was made to select indicators consistent with Healthy People 2010 objectives (9).
In 2012-2013, the indicators were revised with the release of 201 measurable indicators (10).CDC, CSTE, and the National Association of Chronic Disease Directors (NACDD) collaborated to conduct a series of reviews informed by subject-matter expert opinion to make recommendations for revising the indicators.Each recommendation was expected to follow 3 principles: 1) allow states, territories, and large metropolitan areas to uniformly define, collect, and report chronic disease data related to diseases and conditions with a substantial public health effect; 2) ensure that data are consistent with Healthy People 2020 objectives (if possible) (11); and 3) ensure that data are available at the state level for most states and preferably for territories and large metropolitan areas as well.
In 2015, the CDI web tool was released with the 203 indicators published in that year and a few revisions.Revisions included division of the "amount of alcohol excise tax by beverage type" indicator into 3 indicators (beer, wine, distilled spirits), addition of 4 age-specific indicators, and 5 removals due to lack of state-level data.

2022-2024 Indicator Refresh
In 2022, CDC initiated a CDI refresh process that began with a reexamination of the indicators.Much like the reduction in the number of objectives for Healthy People 2030, the CDI also underwent a process including a reduction in the number of indicators.With fewer indicators, the CDI increases its focus on the most pressing public health issues, making it easier to find indicators relevant to the public health work being done.CDC programs reviewed the 203 measurable indicators and recommended which indicators to retain, modify, or remove, and proposed new indicators.Recommendations were expected to meet 3 criteria: 1) the disease or condition has a substantial effect on public health; 2) data for the disease or condition are currently available for most states; and 3) the indicator related to the disease or condition is consistent with public health goals at the national (12) or state level.During the refresh process, programs also aimed to ensure that CDI's presentation of indicators effectively complemented web tools hosted by other CDC programs while retaining its distinctive role as a comprehensive source of data on chronic disease indicators.Funding restrictions prohibited an external process, which was used previously.However, feedback on the refresh process and indicators was obtained from state partners through consultation between CDC programs and relevant partners, as well as presentations and discussions with state-focused groups and organizations, including CSTE, NACDD, and the Association of State and Territorial Health Officials.
The result was a refreshed set of 113 indicators with estimates from 14 data sources (Table 1).Of the 113 indicators, 63 were retained from the previous version, 20 were modified (2 changed data sources and 18 changed measure definitions), and 30 were new (Table 2).Indicators were reorganized into 21 topic areas with the addition of 4 new topic areas in which public health importance and focus has increased during the last several years Many indicators removed are still available on other topic websites or on data custodian websites.For example, the BRFSS Web Enabled Analysis Tool (WEAT) (https://nccd.cdc.gov/weat/#) has a cross-tabulation application that allows users to produce tables showing numbers and percentages of 1 variable by 1 or more additional variables.WEAT can generate estimates of indicators specific to women aged 18 to 44 years (create crosstabulation tables by sex and age group) and for those with a chronic disease (create crosstabulation tables by presence of a condition [eg, arthritis, diabetes]) to obtain subgroup estimates.Links to topic-specific websites are provided as part of the topic-specific landing pages included with the refreshed CDI web tool and links to data source custodian's website are provided in the Data Source section.

2022-2024 CDI Web Tool Refresh
The CDI web tool has received more than 1 million page views since it was first launched in January 2015.As part of the 2022-2024 CDI refresh, CDC also redesigned and enhanced the web tool to modernize the underlying application and improve the tool's usability.Several key features and functions of the CDI web tool were maintained and enhanced.

Indicator definitions and data source descriptions
The CDI web tool has consistently provided standardized definitions and detailed descriptions for each indicator.The detailed definitions include population, numerator, denominator, measure, time period of case definition, summary of background and importance, notes, data source, related objectives or recommendations, secondary CDI topic areas, and related references.This information helps users understand the meaning and context of the indicators.
With the CDI refresh, measure definitions were streamlined to ensure consistency across topic areas and indicators.Twenty-one new topic area landing pages were added to provide users a broad overview of the topic as well as links to where users can find more topic-specific estimates.A new data source section was added that provides information about the data sources, including full name and abbreviation, website, purpose, target population, frequency and mode of data collection, notes, treatment of missing data, data suppression, age-standardization process, and sponsor.

Data visualizations
With the refresh, the CDI web tool maintained and enhanced the ability for users to create interactive charts, graphs, and maps.Users can create exhibits that present data in a visually appealing and easy-to-understand format.Users can select indicators, time periods, and population groups.The ability to stratify estimates by sex and race and ethnicity (when applicable) was retained from the previous version, and the refreshed CDI adds a stratification by age.These visualizations can help users identify patterns, trends over time, and disparities.
Entry into the data visualization section of the CDI web tool was enhanced and 3 entry points are provided: "view maps," "view bar graphs," and "view trends over time" (Figure 1)."View maps."This entry point allows users to view maps of the US (all states, District of Columbia, and territories) for any indicator, year, and group (by sex, age, and race and ethnicity).To create the visualization shown in Figure 1 (middle section): 1) from the "view maps" box, select a topic area category from the dropdown menu (eg, alcohol) and click "go"; 2) select an indicator from the list (eg, binge drinking prevalence among adults); and 3) click "view results" to display the default map (overall estimates for most current year).To make changes (Figure 2, map example), users can select year, "view by," and data type and select the classification type and number of classes.After selections are made, users click "update" to view the map choices selected.Last, when sex, age, or race and ethnicity is selected for the "view by" stratification, a map for a subgroup will be displayed (eg, male).Above the map, there is "view by" option for group level.When using the "view maps" option, only 1 indicator can be viewed at a time.Other visualizations provided in this section include a bar graph by state and a table with all state-level estimates for the indicator selected."View bar graphs."This entry point allows users to view bar graphs for national or state-specific estimates for any indicator, year, and group (by sex, age, and race and ethnicity).To create the visualization shown in Figure 1 ("View Bar Graphs/View Trends Over Time"): 1) from the "view bar graphs" box, users select a location (eg, Georgia) and a topic area category from the dropdown menu (eg, chronic obstructive pulmonary disease); 2) select 1 or more indicators; and 3) click "view results" to display the default bar graph(s) (overall estimates for most current year) for all selected indicators.To make changes for each selected indicator (Figure 2, "Bar Graph/Trends Over Time Example"), users can select year, "view by," and data type.After selections are made, users click "update" to view the graph with choices selected.Other visualizations provided in this section include an accompanying table with the estimates."View Trends Over Time."This entry point allows users to view trend lines for national or state-specific estimates for any indicator, year, and group (by sex, age, and race and ethnicity).This entry point uses the same underlying application as View Bar Graphs; however, the default is to include all years of data available.Refer to the steps for View Bar Graphs.

Comparison report
The comparison report allows users to view all estimates across states, enabling users to identify geographic disparities and variations in disease and risk factor prevalence (Figure 1).Users can select up to 4 locations, including estimates for the overall US and state-level estimates for each of the 50 states, the District of Columbia, and territories.

Data portal
CDI data are published through an open data platform (https:// data.cdc.gov/browse?category=Chronic+Disease+Indicators) that provides users an easy-to-use web-based interface to query and extract data based on their needs.Users can select indicators, geographic locations (national or state-specific), subgroups, and time periods to generate customized data sets and visualizations.Users can also find 21 smaller data sets with estimates for topic areas.With each CDI release, data sets are replaced to include any updated data.Data sets related to the previous version of the CDI (2015-2023) will not be updated but will remain available via the data portal.

CDI Data in Action
State health departments, public health professionals, and policymakers can use the CDI web tool for diverse purposes.They can place a health problem in context by exploring their state's preval-ence of chronic conditions and associated behavioral risk factors.They can compare their data to national estimates and estimates in other states and monitor trends over time to guide decision-making for effective public health action.Decisions might include how to maximize limited resources by prioritizing and targeting health disparities for the most effective strategies to improve health outcomes while reducing disparities in diverse communities and populations.
At CDC, CDI provides estimates across multiple chronic diseases and their risk factors.In this role, CDI balances its presentation of indicators to effectively complement web tools hosted by other CDC programs, while also meeting the needs of smaller programs without dedicated data portals.For topics without dedicated data portals, select CDI data are often integrated into a topic's website and links are provided to direct users to CDI for additional measures and estimates.For example, chronic obstructive pulmonary disease (COPD) is a health topic without a dedicated data portal.CDC's COPD website (www.cdc.gov/copd)provides overall estimates of COPD prevalence and mortality and directs users to CDI for additional COPD measures and stratified estimates.For CDC programs with dedicated data portals, CDI incorporates key indicators for these topics and now provides users with links to additional data sources by topic area.This enhancement makes it easier for users to find estimates they need.For example, indicators related to nutrition, physical activity, breastfeeding, and obesity are provided on the Division of Nutrition, Physical Activity, and Obesity's (DNPAO's) Data, Trends, and Maps site (www.cdc.gov/nccdphp/dnpao/data-trends-maps)(13).While CDI includes 14 indicators for nutrition, physical activity, and weight status, DNPAO's dedicated data portal includes almost 60 indicators that allow users a deeper dive into the topic.
External to CDC, state health departments and other organizations have used CDI data to provide evidence of need.The state health department in Nevada used estimates from the CDI in a presentation for a demonstration waiver for adults with diabetes (14).The Association of State and Territorial Dental Directors included the CDI as a data resource for state-level estimates for oral health indicators in their state surveillance reference guide for developing and implementing a robust state-level oral health surveillance system (15).State

Data Challenges
As with most sources of population health data, several data challenges must be considered.For example, sample size, data quality, and confidentiality considerations might limit the availability of data for some geographies and subgroups.Data reported in the CDI adhere to the criteria stipulated by the data providers, which are described in a new section on data sources.We suggest users be mindful of any major changes in how the indicator is assessed and exercise caution when comparing estimates for the same indicator over time.The "Notes to Users" section aims to provide such pertinent information (eg, changes to indicator definitions).

Conclusion
CDI allows public health practitioners and others to visualize and download national and state chronic disease-related estimates across multiple topic areas and indicators.By refreshing CDI's content and improving its ease-of-use, public health professionals, practitioners, and policymakers can better use these data and tools to guide health planning and actions to improve health.

(
Cognitive Health and Caregiving, Health Status, Sleep, and Social Determinants of Health) (Table 2).Indicators from the previous Overarching Conditions topic area were re-organized into other topic areas (n = 9 indicators) or removed (n = 7 indicators).Several indicators are also listed in additional topic areas (Student Health [n = 16 indicators], Older Adults [n = 6 indicators], and Maternal Health [n = 11 indicators]).The number of indicators included in the refreshed CDI is a decrease from the previous web tool.With fewer indicators, the CDI web tool can minimize overlap with other tools while still presenting key indicators across multiple chronic diseases and their risk factors, including estimates stratified by sex, race and ethnicity, and age.With this refresh, 120 indicators included in the previous version were removed based on the criteria provided above.Twenty-six indicators were removed because data for the indicator were no longer available for most states.Characteristics of other removed indicators were similar across topic areas and included indicators limited to adults with a condition (eg, prevalence of co-occurring conditions [n = 10 indicators] or immunizations [n = 16 indicators]), indicators limited to women aged 18 to 44 years (n = 16 indicators), indicators related to a support or barrier for a disease or risk behavior (n = 24 indicators), cancer indicators related to site-specific incidence or lower mortality rates (n = 9 indicators), indicators that overlapped with another indicator (n = 13 indicators), and indicators for other characteristics (n = 6 indicators).
opinions expressed by authors contributing to this journal do not necessarily reflect the opinions of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions.

Figure 1 .
Figure 1.Annotated screenshot of the home page and entry points for applications in the Chronic Disease Indicators web tool (www.cdc.gov/cdi).

Figure 2 .
Figure 2. Annotated screenshot examples of the "view maps" and "view bar graphs/trends over time" features in the CDI Web tool (www.cdc.gov/cdi).
-level estimates on the adult population meeting the recommended amounts of physical activity provided by the CDI were included in the Bicycling & Walking in the United States 2018 Benchmarking Report (16).Finally, a publication from the official blog of the Association of Diabetes Care & Education Specialists used CDI estimates for the proportion of adults in Guam with diagnosed type 2 diabetes who have taken a diabetes self-management course to help describe the health care challenges facing US-affiliated Pacific Islands communities (17).PREVENTING CHRONIC DISEASE VOLUME 21, E46 PUBLIC HEALTH RESEARCH, PRACTICE, AND POLICY JUNE 2024 The opinions expressed by authors contributing to this journal do not necessarily reflect the opinions of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions.

Table 1 .
Data Sources for Indicators Included in the 2022-2024 Chronic Disease Indicators Refresh and Modernization

Table 2 .
Indicators Included in the 2022-2024 Chronic Disease Indicators Refresh and Modernization, by Topic Area American Community Survey; AEDS, Alcohol Epidemiologic Data System; ANRF, American Nonsmokers' Rights Foundation; BRFSS, Behavioral Risk Factor Surveillance System; CMS, Centers for Medicare & Medicaid Services; CPS-FSS, Current Population Survey Food Security Supplement; NIS, National Immunization Surveys; NSCH, National Survey of Children's Health; NVSS, National Vital Statistics System; PRAMS, Pregnancy Risk Assessment Monitoring System; USRDS, United States Renal Data System; US Cancer DVT, US Cancer Statistics Data Visualizations Tool; WIC, Special Supplemental Nutrition Program for Women, Infants, and Children; WIC-PC, Women, Infants, and Children Participant and Program Characteristics; YRBSS, Youth Risk Behavior Surveillance System.
a Indicator is also in Student Health topic area.b Modified indicators due to changes in measure type.c Indicator is also in Maternal Health topic area.d Modified indicators due to changes in case definition.e Modified indicators due to changes in population.f Modified indicators due to changes in numerator and denominator.g Indicator is also in Older Adults topic area.h Modified indicators due to changes in data source.i Additional indicators are listed in other topic areas.j All indicators are listed in other topic areas.The opinions expressed by authors contributing to this journal do not necessarily reflect the opinions of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions.

Table 2 .
Indicators Included in the 2022-2024 Chronic Disease Indicators Refresh and Modernization, by Topic Area American Community Survey; AEDS, Alcohol Epidemiologic Data System; ANRF, American Nonsmokers' Rights Foundation; BRFSS, Behavioral Risk Factor Surveillance System; CMS, Centers for Medicare & Medicaid Services; CPS-FSS, Current Population Survey Food Security Supplement; NIS, National Immunization Surveys; NSCH, National Survey of Children's Health; NVSS, National Vital Statistics System; PRAMS, Pregnancy Risk Assessment Monitoring System; USRDS, United States Renal Data System; US Cancer DVT, US Cancer Statistics Data Visualizations Tool; WIC, Special Supplemental Nutrition Program for Women, Infants, and Children; WIC-PC, Women, Infants, and Children Participant and Program Characteristics; YRBSS, Youth Risk Behavior Surveillance System.
a Indicator is also in Student Health topic area.b Modified indicators due to changes in measure type.c Indicator is also in Maternal Health topic area.d Modified indicators due to changes in case definition.e Modified indicators due to changes in population.f Modified indicators due to changes in numerator and denominator.g Indicator is also in Older Adults topic area.h Modified indicators due to changes in data source.i Additional indicators are listed in other topic areas.j All indicators are listed in other topic areas.The opinions expressed by authors contributing to this journal do not necessarily reflect the opinions of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions.

Table 2 .
Indicators Included in the 2022-2024 Chronic Disease Indicators Refresh and Modernization, by Topic Area American Community Survey; AEDS, Alcohol Epidemiologic Data System; ANRF, American Nonsmokers' Rights Foundation; BRFSS, Behavioral Risk Factor Surveillance System; CMS, Centers for Medicare & Medicaid Services; CPS-FSS, Current Population Survey Food Security Supplement; NIS, National Immunization Surveys; NSCH, National Survey of Children's Health; NVSS, National Vital Statistics System; PRAMS, Pregnancy Risk Assessment Monitoring System; USRDS, United States Renal Data System; US Cancer DVT, US Cancer Statistics Data Visualizations Tool; WIC, Special Supplemental Nutrition Program for Women, Infants, and Children; WIC-PC, Women, Infants, and Children Participant and Program Characteristics; YRBSS, Youth Risk Behavior Surveillance System.aIndicator is also in Student Health topic area.bModified indicators due to changes in measure type.cIndicator is also in Maternal Health topic area.dModified indicators due to changes in case definition.eModified indicators due to changes in population.fModified indicators due to changes in numerator and denominator.gIndicator is also in Older Adults topic area.hModified indicators due to changes in data source.The opinions expressed by authors contributing to this journal do not necessarily reflect the opinions of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions.
i Additional indicators are listed in other topic areas.j All indicators are listed in other topic areas.

Table 2 .
Indicators Included in the 2022-2024 Chronic Disease Indicators Refresh and Modernization, by Topic Area American Community Survey; AEDS, Alcohol Epidemiologic Data System; ANRF, American Nonsmokers' Rights Foundation; BRFSS, Behavioral Risk Factor Surveillance System; CMS, Centers for Medicare & Medicaid Services; CPS-FSS, Current Population Survey Food Security Supplement; NIS, National Immunization Surveys; NSCH, National Survey of Children's Health; NVSS, National Vital Statistics System; PRAMS, Pregnancy Risk Assessment Monitoring System; USRDS, United States Renal Data System; US Cancer DVT, US Cancer Statistics Data Visualizations Tool; WIC, Special Supplemental Nutrition Program for Women, Infants, and Children; WIC-PC, Women, Infants, and Children Participant and Program Characteristics; YRBSS, Youth Risk Behavior Surveillance System.
a Indicator is also in Student Health topic area.b Modified indicators due to changes in measure type.c Indicator is also in Maternal Health topic area.d Modified indicators due to changes in case definition.e Modified indicators due to changes in population.f Modified indicators due to changes in numerator and denominator.g Indicator is also in Older Adults topic area.h Modified indicators due to changes in data source.i Additional indicators are listed in other topic areas.j All indicators are listed in other topic areas.The opinions expressed by authors contributing to this journal do not necessarily reflect the opinions of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions.

Table 2 .
Indicators Included in the 2022-2024 Chronic Disease Indicators Refresh and Modernization, by Topic Area Proportion of the population protected by a comprehensive smoke-free policy prohibiting smoking in all indoor areas of workplaces and public places, including restaurants and bars ANRF Retained Abbreviations: ACS, American Community Survey; AEDS, Alcohol Epidemiologic Data System; ANRF, American Nonsmokers' Rights Foundation; BRFSS, Behavioral Risk Factor Surveillance System; CMS, Centers for Medicare & Medicaid Services; CPS-FSS, Current Population Survey Food Security Supplement; NIS, National Immunization Surveys; NSCH, National Survey of Children's Health; NVSS, National Vital Statistics System; PRAMS, Pregnancy Risk Assessment Monitoring System; USRDS, United States Renal Data System; US Cancer DVT, US Cancer Statistics Data Visualizations Tool; WIC, Special Supplemental Nutrition Program for Women, Infants, and Children; WIC-PC, Women, Infants, and Children Participant and Program Characteristics; YRBSS, Youth Risk Behavior Surveillance System.a Indicator is also in Student Health topic area.b Modified indicators due to changes in measure type.c Indicator is also in Maternal Health topic area.d Modified indicators due to changes in case definition.e Modified indicators due to changes in population.f Modified indicators due to changes in numerator and denominator.g Indicator is also in Older Adults topic area.h Modified indicators due to changes in data source.i Additional indicators are listed in other topic areas.
c PRAMS New Health insurance coverage in the month before pregnancy among women with a recent live birth c PRAMS Retained Student health j Tobacco Current use of any tobacco product among high school students a YRBSS Modified b Current electronic vapor product use among high school students c PRAMS Modified d j All indicators are listed in other topic areas.The opinions expressed by authors contributing to this journal do not necessarily reflect the opinions of the U.S. Department of Health and Human Services, the Public Health Service, the Centers for Disease Control and Prevention, or the authors' affiliated institutions.